The Glow filter lets you apply a color around the edges of an object.

To set the width and height of the glow, drag the Blur X and Y slider.
To open the Color Picker and set the glow color, click the color control.
To set the sharpness of the glow, drag the Strength slider.
To knock out (or visually hide) the source object and display only the glow on the knockout image, select Knockout.

To apply the glow within the boundaries of the object, select Inner Glow.
Select the quality level for the glow. High is approximate to that of a Gaussian blur. Low maximizes playback performance.